Demographics, Indications, and Revision Rates for Radial Head Arthroplasty: Analysis of Data from the Australian Orthopaedic Association National Joint Replacement Registry.

Background: Population-level data from national arthroplasty registries enable the use and outcomes of arthroplasty procedures to be monitored over time. This study aimed to describe the demographics, indications, and outcomes (up to 15 years) for radial head arthroplasty (RHA) procedures in Australia, as well as the factors associated with an increased likelihood of revision.

Methods: Individual-level deidentified data on demographics and surgery characteristics, including revision surgery, were obtained from the Australian Orthopaedic Association National Joint Replacement Registry for all primary isolated RHA procedures that had been performed from 2007 to 2021. The probability of prosthesis survival was determined using Kaplan-Meier estimates. Cox proportional hazards models were used to calculate hazard ratios (HRs) for revision.

Results: A total of 3,457 primary RHAs were performed during the study period (mean follow-up, 5.6 years; range, 0 to 15 years). The mean age at the time of RHA was 53 years, with female predominance (n = 2,009, 58%). The most common indication for RHA was fracture or dislocation (n = 3,166, 92%), followed by osteoarthritis (n = 232, 7%). The radial head prostheses that were most commonly used were monopolar (n = 3,378, 98%) with a modular design (n = 3,442, 99.6%) and cementless fixation (n = 3,387, 98%). Both metallic and nonmetallic prostheses were used (52% and 48%, respectively). Of the total cohort, 160 revisions (5%) were performed during the 15-year period; most revisions occurred in the first 5 years. The most common revision indication was prosthesis loosening (n = 62, 39%), and 54% of the revisions (n = 87) involved a change of the radial component. In multivariable analysis, primary procedures for osteoarthritis (HR, 1.65; 95% confidence interval [CI], 1.01 to 2.70) or "other" indications (e.g., inflammatory arthritis, osteonecrosis, or tumor) were revised more frequently (HR, 3.68; 95% CI, 1.14 to 11.91) than procedures for fracture or dislocation. Procedures with nonmetallic prostheses had higher rates of revision (HR, 1.61; 95% CI, 1.17 to 2.22) than those with metallic prostheses.

Conclusions: Trauma remained the most prevalent indication for RHA in Australia from 2007 to 2021. Encouragingly, revision rates were low, most notably for RHA that had been performed for fracture or dislocation. The likelihood of revision was highest for RHA procedures performed for osteoarthritis and for an indication other than osteoarthritis or trauma. Nonmetallic prostheses had a higher rate of revision than metallic prostheses.

Level of evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.